Apparatus for producing and simultaneously distributing cement mixes and the like

Description

[0001] The present invention relates to a fixed or self-propelled apparatus for distributing and producing cement mixes, substantially concrete, directly at the time of use in building yards and the like.

[0002] Conventional cement mixes, and particularly concrete for casting into formworks or the like, are usually constituted by proportioned mixes of inert materials, such as sand, gravel and others, with cement of various kinds and with water: the dosage of the components and of the water is chosen according to the structural characteristics which the concrete is to have and according to the type of use thereof.

[0003] Cement mixes are currently usually produced in fixed plants which are specifically equipped, and the resulting product is then transferred to building yards or the like by means of well-known truck mixers, i.e., trucks provided with an inclined and continuously rotatable container inside which the mixture of the components is kept under agitation to prevent changes in the characteristics and properties of the concrete during transport. It is also known that in order to allow the concrete to preserve its strength as much as possible during transport, the fixed mixing plant must be equipped with a forced premixing device.

[0004] Accordingly, truck mixers can be loaded only from a specific plant and after filling it is impossible to proportion the cement and the water.

[0005] The degree of preservation during transport by means of truck mixers is acceptable only for trips limited to a few kilometers and with the aid of suitable additives; moreover, the transport of the ready-mixed concrete in truck mixers also entails the drawback that considerable time and a very high consumption of energy and water are required for the loading, transport, unloading and washing operations. GB 1 107 552 A discloses an apparatus for producing and simultaneously distributing cement mixes according to the preamble of claim 1.

[0006] In order to obviate the drawbacks entailed by the use of truck mixers to transport the ready-mixed concrete, mixing equipment or plants have already been proposed which are structured so as to simultaneously perform at the building yard the mixing of the materials that constitute the concrete and the subsequent unloading into the formworks; in this manner, the well-known deteriorations of ready-mixed concrete caused by transport are avoided and significant advantages are allowed in practice as regards precision in the dosage and mixing of the components, graduality of unloading, and therefore better uniformity and greater strength of the resulting product.

[0007] However, even this method has some drawbacks, especially as regards the energy consumption required by the mixing apparatus. This arises from the fact that the inert products and the cement are made to advance horizontally by means of a conveyor belt which receives the proportioned amounts from overlying containers and are then sent into a screw mixer, into which the mixing water is also sent; said mixer is arranged with a vertical or optionally inclined axis in order to allow the mixed product to rise and exit upwards and then enter the formworks by means of chutes. The vertical arrangement of the mixing screw therefore requires the use of high power to make the product rise along said screw up to the upper exit end; the screw mixer is also usually provided with an inclination which can vary both longitudinally and transversely with respect to the containers of the components, and this entails in practice a considerable bulk.

[0008] Accordingly, the aim of the present invention is to provide an apparatus for manufacturing cement mixes and the like, which is conceived so as to obviate the drawbacks of current fixed plants for ready-mixing the components of the concrete and of the corresponding truck mixers for transporting said concrete, and is most of all capable of producing mixes with precise dosage directly and simultaneously with the unloading into the formworks, and therefore with the advantage of having a considerably reduced energy consumption with respect to currently used loading, transport, unloading and washing systems.

[0009] Another object of the invention is to provide an apparatus for distributing and producing cement mixes which is structured so as to allow to maintain high strength and preservation characteristics for the components during transport and in any weather condition.

[0010] Another object is to allow to proportion the components and the water both manually and automatically or semiautomatically.

[0011] Another object of the invention is to provide an apparatus of the above-specified type which is structured so as to allow to divide the containers, or at least the container for the inert materials, into compartments in order to allow the differentiated proportioning of the products and is also such that it can be used both as a fixed plant and as a transportable plant on self-propelled vehicles, trailers and the like.

[0012] This aim, these objects and others which will become apparent from the following description are achieved by an apparatus for distributing and producing cement mixes, substantially concrete, of the type that uses an endless conveyor belt which can move at the base of separate containers which contain the inert materials and the cement, and a reservoir for the mixing water, so as to allow to form proportioned mixes in a screw mixer, with unloading of the product simultaneously with mixing, said apparatus being constituted, according to the present invention, by a supporting framework, a reservoir for the mixing water, at least one hopper-like prism-shaped container for the inert materials with adjustable discharge openings, and, in a raised position with respect to said hopper for the inert materials, at least one hopper-shaped container with adjustable opening for the cement being anchored to said supporting framework; an endless conveyor belt being interposed between said framework and the discharge openings of said hoppers for the inert materials and for the cement, which are aligned to each other along an inclined plane, said belt being arranged at an angle along the plane of arrangement of said discharge openings, in order to make contact with, and pass beyond, the discharge opening provided on the bottom of said hopper that contains the cement; a screw mixer being associated with said hopper that contains the cement, being arranged so as to have a horizontal axis and being moved by a suitable drive, so as to allow said conveyor belt to convey into said screw proportioned amounts of inert materials and cement and then allow their mixing with proportioned amounts of water drawn from said reservoir, simultaneously with the step for the unloading of the concrete from said screw.

[0013] More particularly, said conveyor belt is arranged, along most of its length, in contact with, and inside, the inclined bottom wall of the hopper that contains the inert materials, so that the opening of said hopper is formed by a cutoff lamina which is arranged so as to be parallel to the belt and at a given distance from the transverse wall of the hopper and so as to leave an end portion of the belt directly in contact with the inert materials, said cutoff lamina being arranged so that its elevation is adjustable, with respect to the underlying belt, to allow operations for feeding inert materials which are proportioned according to requirements.

[0014] The end portion of the belt, which passes beyond the hopper for the inert materials, is instead located below an opening formed in the bottom of the container for the cement, and its discharge port is adjusted by a choke lamina which can move externally and parallel to the bottom of the container by means of a double-action actuation piston which is rigidly coupled to said bottom.

[0015] Moreover, an additional choke lamina for the inert materials before their mixing with the cement is located in the inclined transverse part that divides the two hoppers; its elevation is adjustable with respect to the underlying belt both manually and by means of mechanical, electrical or similar controls.

[0016] Likewise, vibrating devices which are suitable to facilitate the descent of the materials onto the conveyor belt are associated with the walls of the hoppers for the inert materials and for the cement, whilst conventional continuous weighing cells for the inert materials and for the cement are associated with said belt.

[0017] Further characteristics and advantages of the present invention will become apparent from the following detailed description, given with reference to the accompanying drawings, which are provided only by way of non-limitative example and wherein:

figure 1 is a partially sectional schematic side view of an apparatus for producing, mixing and simultaneously unloading cement mixes, executed according to the present invention;

figure 2 is an enlarged-scale transverse sectional view of figure 1, taken along the plane II-II of said figure;

figure 3 is also a transverse sectional view of said figure 1, taken along the plane III-III;

figure 4 is an enlarged-scale sectional view, showing only the assembly constituted by the cement hopper and the underlying mixing screw, shown in figure 1;

figure 5 is an enlarged-scale front view, showing in axonometric projection only the front part of the cement hoppers-mixing screw assembly;

figures 6 and 7 are sectional views of two different embodiments of the cement hopper and of the corresponding screw; whilst

figure 8 is a schematic side view of a flatbed truck on which the apparatus of figure 1 is installed.

[0018] With reference to the above figures, and in particular to figures 1 to 4, the apparatus according to the invention is substantially constituted by a quadrangular framework 1 which constitutes a flat supporting base on which a container body is anchored by means of uprights 2-2a which rise from said framework; said body is substantially shaped like an inverted wedge, i.e., it is constituted by two substantially rectangular flat walls 3 and 4, which diverge with respect to each other so that the vertex 5 (figure 1) is in contact with the supporting framework, and by two side walls 6-6a (figure 2) which are substantially triangular and diverge so as to give the container the shape of a hopper which is substantially shaped like a truncated pyramid.

[0019] Said inverted-wedge container is also divided, by means of an intermediate wall 7, into two containers (figure 1), one of which, designated by the reference numeral 8, is meant to contain the inert materials (sand, gravel or the like), whilst the other one, in a raised position and designated by the reference numeral 9, is meant to contain the cement; the container 8 for the inert materials is of the open-top type, whilst the container 9 for the cement is provided with a closure wall 9a with an opening 9b for introducing the material and with an inclined wall 9c (figure 1) which constitutes the chute-shaped bottom of said container 9; said bottom is therefore separated from the underlying continuous wall 4. In the space between the inclined wall 4 (figure 1) and the bottom wall 9c of the cement container 9 there is an endless conveyor belt 10, which is stretched between a free roller 11 and a motorized roller 12 and whose length is such as to correspond to the distance between the corner region 5 and practically all of the extension of the bottom wall 9c of the cement container 9, as will become apparent hereinafter.

[0020] As clearly shown in figure 2, said conveyor belt 10 has such a width that it can be accommodated in a quadrangular recess 4a formed along the entire length of the wall 4 (and not shown in figure 1), so that the moving belt is constantly in contact with the inert materials contained in the hopper 8.

[0021] In order to prevent the inert materials from entering the recess 4a, at the top of the sides of the vertical walls 4b of said recess it is possible to anchor flexible laminae (not shown) which are placed in sliding contact with the belt of the conveyor (figure 2).

[0022] Moreover, the belt 10 of the conveyor is provided, as in conventional conveyors, with equidistant transverse strips 13 for moving the material upwards, and is installed so that it can slide on a fixed plane 14 to prevent the flexing of said belt under the weight of the material during transport; likewise, in order to prevent the considerable weight of the inert material contained in the hopper 8 from bearing on the entire length of the underlying conveyor belt, a wedge-shaped cover 15 is anchored to the opposite walls 6-6a (figures 1 and 2), is arranged transversely to the belt, and is shorter than the portion of conveyor belt which is included in the hopper 8, so as to leave only two belt portions in contact with the material: an exposed portion 16 at the lower end of the conveyor and an exposed portion 17 at the other end (figure 1). Moreover, a cutoff or choke lamina 18 (figure 1) is anchored to the lower end of the transverse cover 15 so that it can move at right angles to the conveyor, is arranged parallel to the belt of said conveyor, and is suitable to form a gap of adjustable width between the lamina 18 and the belt 10.

[0023] Said adjustable gap allows to proportion the amount of inert materials fed by the initial portion 16 of the belt; moreover, again in order to allow adjustable proportioning of the inert materials, at the base of the dividing wall 7 there is a similar choke lamina 19 which is parallel to the conveyor and can move vertically to it.

[0024] In order to allow proportioning of the cement contained in the hopper 9, in the bottom wall 9c of said hopper there is a quadrangular opening 20, whose size can be changed by means of a choke lamina 21 (figures 1 and 4) which can slide in contact with said bottom wall and is actuated by a double-action actuation piston 22.

[0025] The inert materials and the cement can be proportioned by shifting the choke laminae with manual or mechanical systems or even automatically or semiautomatically. The lamina 21 provided on the bottom of the cement hopper can be pushed into contact against the wall 7 and can thus hermetically close the discharge opening 20; this can be useful during the transport of the apparatus, when the belt is not moving.

[0026] The inclined wall 4, with which the conveyor belt is associated, is provided, at its end connected to the outside wall of the cement hopper 9, with a substantially semicylindrical flared portion 23 (figures 1-4-6) which is arranged transversely to the belt 10 and in which a vane screw 24 is rotatably installed to mix the inert materials and the cement which are fed by gravity from the end of the conveyor.

[0027] A mix collecting body 25 is also associated with said mixing screw at its outlet end, and a chute 26 (figure 5) is associated with said body and can be orientated both vertically and horizontally to introduce the concrete mix into the formworks simultaneously with the production of said mix.

[0028] In order to move the conveyor 10, there is an independent drive which is keyed on the traction roller 12, whilst for the rotation of the screw 24 there is a separate drive which is keyed on the shaft 24a of said screw.

[0029] Finally, the apparatus is provided with a mixing water reservoir 32, from which said water can be sent, in a proportioned amount, into the screw (figure 5) by means of tubes 32a and a corresponding pump (not shown).

[0030] However, in practice and according to requirements, both the conveyor 10 and the screw 24 can be moved by means of a single motor which has, for example, a pulley which is associated with the motor of the conveyor and can actuate, by means of a chain or toothed belt, another pulley which is associated with the shaft of the screw.

[0031] Moreover, in the case of an apparatus installed on the bed 1a of a truck, as shown schematically in figure 8, the power take-off for moving the conveyor and the screw can be taken either from the gearbox of the truck engine or from the device for tilting the bed of a tilt-bed truck.

[0032] The apparatus described above can also have partitions 27 (figure 8) provided in the hoppers for the inert materials and for the cement, for the differentiated proportioning of different materials: in said partitions, the horizontal side can also be arranged at a short distance from the ribbon, so as to form an opening whose size can be adjusted by means of laminae 28 which can slide in contact with said partitions; said laminae, in addition to allowing independent proportionings of the various inert materials (or cement), allow to hermetically close the various compartments during the transport of the apparatus.

[0033] Also according to the invention, one or more load cells 29 can be associated with the conveyor 10 for the continuous electronic weighing of the load supported by the conveyor, as shown in figure 6. Likewise, vibrating devices 31-31a et cetera (figure 1), suitable to facilitate the descent of the material, can be applied to the walls of the hoppers 8 and 9.

[0034] Moreover, the choke lamina 21 of the discharge port 20 of the cement hopper can be replaced with a volumetric dosage device 30 of the star type (figure 7) in which the rotation rate can be adjusted according to requirements.

[0035] Finally, the hopper for the inert materials can be provided, in an upward region, with a protective net 33 (figure 1).

[0036] From the above description, in practice, it has been possible to note that the apparatus according to the invention allows to obtain a plurality of practical and economic advantages with respect to conventional truck mixers, which can be summarized as follows:

-- various kinds of concrete obtained with the above-described apparatus at the time of unloading, with forced mixing and precise proportioning, have excellent strength and preservation during transport;

-- there is a high reduction in energy consumption, since the motor or motors that perform mixing are used only at the time of unloading;

-- the possibility to vary the proportions even during the unloading of the mix, and a reduced consumption of water for washing the plant.

[0037] Finally, it is evident that the invention as described and illustrated is in practice susceptible of structurally and functionally equivalent modifications and variations without abandoning the scope of the appended claims.

[0038] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. An apparatus for producing and simultaneously distributing cement mixes, substantially concrete, which uses an endless conveyor belt (10) which can move at the base of separate containers or hoppers (8,9) containing the inert materials and the cement, and a reservoir (32) for the mixing water, so as to allow to form proportioned mixes in a screw mixer (24), with unloading of the product simultaneously with mixing, characterized in that said apparatus is constituted by a supporting framework (1), a reservoir for the mixing water (32), at least one hopper-like prism-shaped container (8) for the inert materials with adjustable discharge openings (16,17), and, in a raised position with respect to said hopper (8) for the inert materials, at least one hopper-shaped container (9) with adjustable opening (20) for the cement being anchored to said supporting framework (1); an endless conveyor belt (10) being interposed between said framework (1) and the discharge openings (16,17) of said hoppers for the inert materials (8) and for the cement (9), which are aligned with respect to each other along an inclined plane, said belt (10) being arranged at an angle along the plane of arrangement of said discharge openings (16,17), in order to make contact with, and pass beyond, the discharge opening (20) provided on the bottom of said hopper (9) that contains the cement; a screw mixer (24) being associated with said hopper (9) that contains the cement, being arranged so as to have a horizontal axis and being moved by a suitable drive, so as to allow said conveyor belt (10) to convey into said screw (24) proportioned amounts of inert materials and cement and then allow their mixing with proportioned amounts of water drawn from said reservoir (32), while simultaneously unloading the concrete from said screw (24).

2. An apparatus according to claim 1, characterized in that said conveyor belt (10) is, along most of its length, arranged internally and in contact with the inclined bottom wall (4) of the hopper (8) that contains the inert materials, the opening (16) of said hopper being formed by a cutoff lamina (18) which is arranged parallel to the belt and at a given distance from the transverse wall (3) of the hopper (8), so as to leave an end portion of the belt (10) directly in contact with the inert materials, said cutoff lamina (18) being arranged so that its elevation can be adjusted with respect to the underlying belt (10) in order to allow feeds of inert materials which are proportioned according to requirements.

3. An apparatus according to claims 1 and 2, characterized in that the end portion of the conveyor belt (10), which passes beyond said hopper (8) for the inert materials, is arranged below an opening (20) formed on the bottom (9c) of the cement hopper (9), and in that the adjustment of its discharge port is achieved by means of a choke lamina (21) which can move externally and parallel to the bottom of the container (9) by means of a double-action actuation piston (22) which is rigidly coupled to said bottom (9c).

4. An apparatus according to one or more of the preceding claims, characterized in that an additional choke lamina (19) for the inert materials before their mixing with the cement is associated on the inclined transverse wall (7) that divides said two hoppers (8,9), said lamina (19) being movable in contact with said transverse wall (7) and being adjustable in its elevation with respect to the underlying conveyor belt (10), with both manual and mechanical, electrical, or similar actuation.

5. An apparatus according to one or more of the preceding claims, characterized in that vibrating devices (31,31a) are associated with one or more walls (3,7) of the hoppers (8,9) for the inert materials and for the cement and are suitable to facilitate the descent of the materials onto the conveyor belt (10), whilst conventional electronic continuous weighing cells, or electronic or mechanical distance indicators, for the inert materials and for the cement, are associated with said belt (10).

6. An apparatus according to the preceding claims, characterized in that it has, for the discharge opening (20) of the cement hopper (9), a volumetric dosage device (30) of the star type with adjustable rotation rate.

7. An apparatus according to the preceding claims, characterized in that partitions or dividing walls (27) are provided within said hoppers (8,9) for the inert materials and for the cement and allow differentiated proportionings of the materials.

8. An apparatus according to the preceding claims, characterized in that said conveyor belt (10) and said screw (24) are actuated by independent motor means or also through a single drive.

9. An apparatus according to the preceding claims, characterized in that the movement of the belt (10) and of the screw (24) is performed by drawing power from the tilting device provided on tilt-bed trucks or even from the gearbox of said trucks.

Ansprüche

1. Vorrichtung zur Herstellung und gleichzeitigen Verteilung von Zementgemischen, im wesentlichen Beton, welche ein Endlosförderband (10), das sich an der Basis von separaten Behältern oder Trichtern (8, 9), die die inerten Materialien und den Zement enthalten, bewegen kann, und einen Vorratsbehälter (32) für das Mischwasser verwendet, um zu ermöglichen, proportionierte Gemische in einem Schneckenmischer (24) zu bilden, wobei das Produkt gleichzeitig mit dem Mischen ausgeladen wird, dadurch gekennzeichnet, daß die Vorrichtung aus einem Tragrahmenwerk (1), einem Vorratsbehälter für das Mischwasser (32), mindestens einem trichterartigen, prismenförmigen Behälter (8) für die inerten Materialien mit einstellbaren Auslaßöffnungen (16, 17) und, in einer angehobenen Position bezüglich des Trichters (8) für die inerten Materialien, mindestens einem trichterförmigen Behälter (9) mit einer einstellbaren Öffnung (20) für den Zement, welcher an dem Tragrahmenwerk (1) verankert ist, besteht; wobei ein Endlosförderband (10) zwischen das Rahmenwerk (1) und die Auslaßöffnungen (16, 17) der Trichter für die inerten Materialien (8) und für den Zement (9) eingefügt ist, die relativ zueinander entlang einer schrägen Ebene ausgerichtet sind, wobei das Band (10) in einem Winkel entlang der Ebene der Anordnung der Auslaßöffnungen (16, 17) angeordnet ist, um mit der Auslaßöffnung (20), die an der Unterseite des Trichters (9) vorgesehen ist, der den Zement enthält, einen Kontakt herzustellen und an dieser vorbeizulaufen; wobei ein Schneckenmischer (24) dem Trichter (9), der den Zement enthält, zugeordnet ist und so angeordnet ist, daß er eine horizontale Achse aufweist, und durch einen geeigneten Antrieb bewegt wird, um zu ermöglichen, daß das Förderband (10) proportionierte Mengen von inerten Materialien und Zement in die Schnecke (24) befördert, und dann ihr Mischen mit proportionierten Mengen von Wasser zu ermöglichen, das aus dem Vorratsbehälter (32) entnommen wird, während gleichzeitig der Beton aus der Schnecke (24) abgeladen wird.

2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß das Förderband (10) entlang des meisten seiner Länge intern und in Kontakt mit der schrägen Bodenwand (4) des Trichters (8) angeordnet ist, der die inerten Materialien enthält, wobei die Öffnung (16) des Trichters aus einer abgeschnittenen Lamelle (18) gebildet ist, die parallel zum Band und in einem gegebenen Abstand von der Querwand (3) des Trichters (8) angeordnet ist, um einen Endteil des Bandes (10) direkt in Kontakt mit den inerten Materialien zu belassen, wobei die abgeschnittene Lamelle (18) so angeordnet ist, daß ihre Höhe bezüglich des darunterliegenden Bandes (10) eingestellt werden kann, um Zuführungen von inerten Materialien zu ermöglichen, die gemäß den Anforderungen proportioniert sind.

3. Vorrichtung nach den Ansprüchen 1 und 2, dadurch gekennzeichnet, daß der Endteil des Förderbandes (10), der jenseits des Trichters (8) für die inerten Materialien verläuft, unterhalb einer Öffnung (20) angeordnet ist, die am Boden (9c) des Zementtrichters (9) ausgebildet ist, und daß die Einstellung seiner Auslaßöffnung durch eine Drossellamelle (21) erreicht wird, die sich extern und parallel zum Boden des Behälters (9) durch einen doppelwirkenden Betätigungskolben (22) bewegen kann, der starr mit dem Boden (9c) gekoppelt ist.

4. Vorrichtung nach einem oder mehreren der vorangehenden Ansprüche, dadurch gekennzeichnet, daß eine zusätzliche Drossellamelle (19) für die inerten Materialien vor ihrem Mischen mit dem Zement an der schrägen Querwand (7) angeschlossen ist, welche die zwei Trichter (8, 9) unterteilt, wobei die Lamelle (19) in Kontakt mit der Querwand (7) beweglich ist und in ihrer Höhe bezüglich des darunterliegenden Förderbandes (10) mit sowohl manueller als auch mechanischer, elektrischer oder ähnlicher Betätigung einstellbar ist.

5. Vorrichtung nach einem oder mehreren der vorangehenden Ansprüche, dadurch gekennzeichnet, daß Vibrationsvorrichtungen (31, 31a) einer oder mehreren Wänden (3, 7) der Trichter (8, 9) für die inerten Materialien und für den Zement zugeordnet sind und geeignet sind, um die Abwärtsbewegung der Materialien auf das Förderband (10) zu erleichtern, während herkömmliche, elektronische, durchgehende Gewichtungszellen oder elektronische oder mechanische Abstandsanzeiger für die inerten Materialien und für den Zement dem Band (10) zugeordnet sind.

6. Vorrichtung nach den vorangehenden Ansprüchen, dadurch gekennzeichnet, daß sie für die Auslaßöffnung (20) des Zementtrichters (9) eine Volumendosierungsvorrichtung (30) vom Stemtyp mit einstellbarer Drehgeschwindigkeit aufweist.

7. Vorrichtung nach den vorangehenden Ansprüchen, dadurch gekennzeichnet, daß Trennwände oder Unterteilungswände (27) innerhalb der Trichter (8, 9) für de inerten Materialien und für den Zement vorgesehen sind und differenzierte Proportionierungen der Materialien ermöglichen.

8. Vorrichtung nach den vorangehenden Ansprüchen, dadurch gekennzeichnet, daß das Förderband (10) und die Schnecke (24) durch unabhängige Motoreinrichtungen oder auch durch einen einzelnen Antrieb betätigt werden.

9. Vorrichtung nach den vorangehenden Ansprüchen, dadurch gekennzeichnet, daß die Bewegung des Bandes (10) und der Schnecke (24) durch Abziehen von Kraft von der Kippvorrichtung, die an Kippbett-Lastkraftwagen vorgesehen ist, oder auch von dem Getriebekasten der Lastkraftwagen durchgeführt wird.

Revendications

1. Un dispositif pour la production et la distribution simultanée de mélanges de ciment, essentiellement du béton, qui utilise une bande transporteuse sans fin (10) susceptible de se déplacer à la base de récipients ou trémies séparés (8,9) qui contiennent les matériaux inertes et le ciment, et un réservoir (32) pour l'eau de gâchage, permettant la formation de mélanges proportionnés dans un mélangeur à vis (24), le produit étant déchargé simultanément avec son mélange, caractérisé en ce que ledit dispositif est constitué par un cadre de support (1), un réservoir pour l'eau de gâchage (32), au moins un récipient prismatique en forme de trémie (8) pour les matériaux inertes avec des ouvertures de déchargement réglables (16, 17) et, à une position surélevée par rapport à ladite trémie (8) pour les matériaux inertes, au moins un récipient (9) en forme de trémie, avec une ouverture réglable (20) pour le ciment, ancré audit cadre de support (1) ; une bande transporteuse sans fin (10) étant interposée entre ledit cadre (1) et lesdites ouvertures de déchargement (16,17) desdits trémies pour les matériaux inertes (8) ainsi que pour le ciment (9) qui sont alignées l'une par rapport à l'autre selon un plan incliné, ladite bande (10) étant agencée selon un angle suivant le plan de l'agencement desdites ouvertures de déchargement (16, 17) afin de faire contact avec, et passer par, l'ouverture de déchargement (20) prévue au fond de ladite trémie (9) contenant le ciment ; un mélangeur à vis (24) étant associé à ladite trémie (9) contenant le ciment, et étant agencé afin d'avoir un axe horizontal et étant déplacé grâce à un moyen adéquat d'entraînement, afin de permettre le transport par ladite bande transporteuse (10) des quantités proportionnées de matériaux inertes et de ciment audit mélangeur à vis (24) et de permettre ensuite leur mélange avec des quantités proportionnées d'eau tirée dudit réservoir (32), tout en déchargeant simultanément le béton dudit mélangeur à vis (24).

2. Un dispositif selon la revendication 1 caractérisé en ce que ladite bande transporteuse (10) est, sur la plus grande partie de sa longueur, agencée à l'intérieur par rapport à la paroi de fond inclinée (4) de la trémie (8) qui contient des matériaux inertes et en contact avec celle-ci, l'ouverture (16) de ladite trémie étant formée par une lame découpée (18) agencée parallèlement à la bande et à une distance donnée par rapport à la paroi transversale (3) de la trémie (8) afin de laisser une partie d'extrémité de la bande (10) directement en contact avec des matériaux inertes, ladite lame découpée (18) étant agencée de sorte que son élévation puisse être réglée par rapport à la bande (10) sous-jacente afin de permettre l'alimentation en matériaux inertes qui sont proportionnés en fonction des besoins.

3. Un dispositif selon la revendication 1 et 2, caractérisé en ce que la partie terminale de la bande transporteuse (10) qui passe en-dessous de ladite trémie (8) pour les matériaux inertes est agencée en-dessous d'une ouverture (20) formée dans le fond (9c) de la trémie (9) pour le ciment, et en ce que le réglage de son ouverture de décharge est obtenu grâce à une lame de bouchage (21) susceptible d'être déplacée à l'extérieur et en parallèle par rapport au fond du récipient (9) au moyen d'un piston d'actionnement à double course (22), couplé de manière rigide par rapport audit fond (9c).

4. Un dispositif selon l'une quelconque des revendications précédentes, caractérisé en ce que une lame de bouchage supplémentaire (19) pour les matériaux inertes avant le mélange avec le ciment est associée à la paroi transversale inclinée (7) qui divise les deux trémies (8,9), ladite lame (19) étant susceptible de se déplacer en contact avec ladite paroi transversale (7) et étant réglable en ce qui concerne son élévation par rapport à la bande transporteuse sous-jacente (10), au moyen d'un actionnement manuel et mécanique, électrique ou similaire.

5. Un dispositif selon l'une ou plusieurs des revendications précédentes, caractérisé en ce que des organes vibrants (31, 31a) sont associés avec une ou plusieurs parois (3,7) des trémies (8,9) pour les matériaux inertes, ainsi que pour le ciment et sont adaptés pour faciliter la descente du matériau sur la bande transporteuse (10), au moyen de cellules conventionnelles de pesée électronique en continu, des indicateurs de distance de type électronique ou mécanique pour les matériaux inertes ainsi que pour le ciment étant associé à ladite bande (10).

6. Un dispositif selon les revendications précédentes, caractérisé en ce qu'il présente, pour l'ouverture de décharge (20) de la trémie (9) pour le ciment, un dispositif de dosage volumétrique (30) du type à étoile avec une vitesse de rotation réglable.

7. Un dispositif selon les revendications précédentes, caractérisé en ce que des cloisons ou des parois divisionnaires (27) sont prévues à l'intérieur desdites trémies (8,9) pour les matériaux inertes et pour le ciment, permettant une différenciation des proportions des matériaux.

8. Un dispositif selon les revendications précédentes, caractérisé en ce que ladite bande transporteuse (10) et ladite vis (24) sont entraînées au moyen de moteurs indépendants ou, également, au moyen d'un entraînement commun.

9. Un dispositif selon les revendications précédentes, caractérisé en ce que le déplacement de la bande (10) ainsi que de la vis (24) est obtenu en extrayant de la puissance d'un organe basculant prévu sur des véhicules à lit basculant ou même par la boîte de vitesse desdits véhicules.

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